Pulse resistors

Pulse resistors are a special kind of power resistor. Here, the resistor must absorb the power of several kW in a couple of ms (timing pulse) as heat.  

Our printed pulse resistors can absorb high amounts of power (several hundred kW) for short periods of time (ms) and replace expensive ceramic resistors. Compared with traditional resistor assemblies, the primary advantages of these printed pulse resistors is the high integration capability of the components and associated reduction in volume, which makes them more robust and affordable.

Another advantage is the high degree of dependability when subject to variable thermal loads; this was demonstrated in temperature change tests (-40°C / +125°C) up to 3,000 cycles. Conventional systems consist of very different materials (ceramic, FR4, solder) and have very different degrees of linear expansion under changing temperatures. This can result in premature breakdown of the assembly. Conductive polymers and circuit boards have almost identical properties, so this problem does not occur under the conditions mentioned above.

In many cases, conventional components in assemblies are only available as wired versions, which require elaborate component assembly and result in undependable solder connections. As wired components, pulse resistors are also significantly larger than standard resistors, so they require a lot of room and a more elaborated manufacturing process, cause more procurement and warehousing expenses, and harbor risks of error at the soldering joints of the wired components.

Printed resistors by Würth Elektronik FLATcomp Systems overcome these handicaps. They can even be placed on the inner layers of a multilayer and thus don’t take up assembly space that is so scarce on the outer layers.

Dimensions of the resistor are designed based on the pulse load. Würth Elektronik FLATcomp Systems specialists identify the dimensions you need for your specific application. Contact us at flatcomp@we-online.de.

Examples of practical applications

  • EMC protection  
  • Defibrillators (medical technology)  
  • Charge and discharge resistors for storage capacitors  
  • (Product information Special resistors)  
  • Tecreport 07